Skewed Query - forum topic by ciw916

I seem to be having trouble with a query that I inherited from another developer.  I'm told this is running a 99% skew. Would anybody be able to tell me what looks so skewed about this table?
 
create table ntl_prd_qmtmptbls.calls_tz_cw as (
select
cust_id,
cust_line_seq_id,
acss_call_dt,
call_start_tm,
call_end_tm,
acss_call_ctr_time_zn,
acss_call_id,
call_start_dttm,
call_end_dttm,
acss_user_id,
--cast (format dh.datekey as date 'yyyy-mm-dd') as datekey_formatted,
CASE
WHEN c.acss_call_ctr_time_zn = 'mst' and dh.isindaylightsavings = '1' THEN c.call_start_dttm + interval '3' hour
WHEN c.acss_call_ctr_time_zn = 'mst' and dh.isindaylightsavings = '0' THEN c.call_start_dttm + interval '2' hour
WHEN c.acss_call_ctr_time_zn LIKE 'H%' and dh.isindaylightsavings = '1' THEN c.call_start_dttm + interval '5' hour
WHEN c.acss_call_ctr_time_zn LIKE 'H%' and dh.isindaylightsavings = '0' THEN c.call_start_dttm + interval '4' hour
WHEN c.acss_call_ctr_time_zn = 'mdt' THEN c.call_start_dttm + interval '2' hour
WHEN c.acss_call_ctr_time_zn LIKE 'C%' THEN c.call_start_dttm + interval '1' hour
WHEN c.acss_call_ctr_time_zn LIKE 'P%' THEN c.call_start_dttm + interval '3' hour
ELSE c.call_start_dttm END acss_call_start_dttm_est,
CASE
WHEN c.acss_call_ctr_time_zn = 'mst' and dh.isindaylightsavings = '1' THEN c.call_end_dttm + interval '3' hour
WHEN c.acss_call_ctr_time_zn = 'mst' and dh.isindaylightsavings = '0' THEN c.call_end_dttm + interval '2' hour
WHEN c.acss_call_ctr_time_zn LIKE 'H%' and dh.isindaylightsavings = '1' THEN c.call_end_dttm + interval '5' hour
WHEN c.acss_call_ctr_time_zn LIKE 'H%' and dh.isindaylightsavings = '0' THEN c.call_end_dttm + interval '4' hour
WHEN c.acss_call_ctr_time_zn = 'mdt' THEN c.call_end_dttm + interval '2' hour
WHEN c.acss_call_ctr_time_zn LIKE 'C%' THEN c.call_end_dttm + interval '1' hour
WHEN c.acss_call_ctr_time_zn LIKE 'P%' THEN c.call_end_dttm + interval '3' hour
ELSE c.call_end_dttm END acss_call_end_dttm_est
from ntl_prd_qmtmptbls.calls_cw c
join ntl_prd_qmtbls.date_help dh
on c.acss_call_dt = cast(datekey as date format 'YYYYMMDD')
) with data primary index (cust_id, cust_line_seq_id) ;